Dimethyl disulfide is a widely used chemical raw material, which can be used for synthesizing methanesulfonyl chloride and methanesulfonic acid products. In addition, dimethyl disulfide is an organic solvent often used in polymerization and cyanation reactions. In the food industry, dimethyl sulfide is allowed to be used as an edible flavor. Besides, dimethyl disulfide can be used as a catalyst and passivating agent in petroleum industry, an odor agent for city gas, an industrial cleaning agent, a pesticide penetrating agent and the like. Therefore, it is a research hotspot for the skilled person in the art to study the preparation technology of dimethyl disulfide.
In theory, it is an available way for preparing dimethyl disulfide by catalytic oxidation of raw material methanthiol (4CH3SH+O2→2CH3SSCH3+2H2O). However researches of industrial production process of preparing dimethyl disulfide by catalytic oxidation of raw material methanthiol haven't been under way. Chinese patent application CN102816093A discloses a method for preparing dimethyl disulfide by oxidization of methanthiol, comprising introducing a mixture gas of methanthiol, oxygen and nitrogen dioxide with molar ratio 4:1.25:0.2 into a tower reactor to perform oxidation reaction in the presence of an emulsifying agent by controlling the molar ratio of methanthiol to emulsifying agent to 1:10-30 at a reaction temperature of 10-150° C. and a pressure of 0.01-0.1 MPa to produce a reaction product, then after 10 to 20 minutes' standing, dimethyl disulfide is separated from the reaction product. In this method a qualified dimethyl disulfide product is prepared by using nitrogen dioxide as a catalyst and by reaction, separation and rectification processes.
Although researches of industrial production process of preparing dimethyl disulfide by catalytic oxidation of raw material methanthiol haven't been under way, and there lacks of intensive study on catalyst for catalytic oxidation of methanthiol, the process of preparing dimethyl disulfide by catalytic oxidation of methanthiol still has vast development potential because it has some advantages such as simple and safe. In order to realize its industrial production, the problem to be solved in the prior art is to develop new catalysts to improve the catalytic conversion rate of methanthiol.